This problem has been slow coming, but now it looks like the RPM sensor
has finally failed (174K). BUT before I dig into this pig-of-a-repair, does
anyone know where the RPM sensor signal is routed? I'd like to put a scope on that line, or (as I did on my S90) slip a small signal amp in to boost up
this sagging signal to see if that's the failing part.

My Haymes manual doesn't list it by that name in the schematic section. It does call out an "Impulse Sender" which appears to be routed to the spark
controller. But the schematic is so poor it is hard to read.

Anyone have the answer?

Charlie

 

Why don't you just follow the wire from the top of the housing to where it plugs in into the harness? This the set up in the 940s anyway...

 

my understanding is that the sensor is mounted into the top of the flywheel housing - a little tricky to "follow" that. Schematics are a little more useful and safer bet.